test file for #644 (fixed with previous commit?)

test/cgen/returnscrut.kk

@@ -0,0 +1,29 @@
+// Issue: https://github.com/koka-lang/koka/issues/644
+fun main()
+  println("Compiled")
+
+type token
+  Int
+
+value struct token-iter<h>
+  chars: vector<char>
+  idx: ref<h, int>
+
+fun token-iter/next(token-iter: token-iter<h>): <div, read<h>, write<h>> maybe<(int, token)>
+  // Strange code below to work around issues with early returns in Koka 3.1.2.
+  // (https://github.com/koka-lang/koka/discussions/643)
+
+  // Skip whitespace
+  val next-char0 =
+    match Nothing
+      Just((_idx, _c)) ->
+        if True then
+          return token-iter.next
+        else
+          Nothing
+      Nothing -> Nothing
+  val tmp = match next-char0
+          Nothing -> return Nothing
+          Just(c) -> c
+  val (_char-idx, _char) = tmp
+  Nothing

test/cgen/returnscrut.kk.out

@@ -0,0 +1 @@
+Compiled